Effects of 2-APB on store-operated Ca²⁺ channel currents of hepatocytes after hepatic ischemia/reperfusion injury in rats

Abstract

The effects of hepatic ischemia/reperfusion (I/R) injuries on hepatocellular viability and store-operated calcium current (Isoc) in isolated rat hepatocytes and the effects of 2-APB on store-operated calcium current (Isoc) in isolated rat hepatocytes after hepatic ischemia/reperfusion injuries were studied. Hepatic ischemia and reperfusion injury model was establised and whole cell patch-clamp techniques were used to investigate the effects of 2-APB on Isoc. The results showed that ischemia/reperfusion injuries could significantly reduce hepatocellular viability and further increase Isoc in hepatocyte and 2-APB (20, 40, 60, 80, 100 μmol/L) produced a concentration-dependent decrease of Isoc with IC₅₀ value of 64.63±10.56 μmol/L (n=8). It was concluded that ischemia/ reperfusion injuries could reduce hepatocellular viability, probably through increased Isoc in hepatocytes and 2-APB had a protective effect on ischemia/reperfusion-induced liver injury, probably though inhibiting Isoc.

Keywords

hepatic-ischemia reperfusion injuries / hepatocytes / store-operated calcium current / store-operated calcium channel / calcium channel blockers

References

[1] PutneyJ W, McKayR R. Capcitative calcium entry channels. Bioessays, 1999, 21: 38-38

[2] BarrittG J. Receptor-activated Ca²⁺ inflow in animal cells: a variety of pathways tailored to meet different intracellular Ca²⁺ signaling requirements. Biochem J, 1999, 337: 153-153

[3] FierroL, ParekhA B. Substantial depletion of the intracellular Ca²⁺ store is require for macroscopic activation of the Ca²⁺ release-activated Ca²⁺ current in rat basophilic leukemia cell. J Physiol, 2000, 522(2): 247-247

[4] RychkovG, BreretonH M, HarlandM L, et al.. Plasma membrane Ca²⁺ release-activated Ca²⁺ channel with a high selectivity for Ca²⁺ identified by patch-clamp recording in rat liver cells. Hepatology, 2001, 33: 938-938

[5] MaruyamaT, KanajiT, NakadeS, et al.. 2-APB, 2-aminoethoxydiphenyl borate, a membrane-penetrable modulator of ins (1,4,5) P₃-induce Ca²⁺ release. J Biochem, 1997, 122(3): 498-498

[6] IwasakiH, MoriY, UchidaK, et al.. 2-aminoethoxydiphenyl borate (2-APB) inhibits capacitative calcium entry independently of the function of inositol 1, 4, 5-trisphospate receptors. Receptors Channels, 2001, 7(6): 429-429

[7] BootmanM D, CollinsT J, MackenzieL, et al.. 2-aminoethoxydiphenyl borate (2-APB) is a reliable blocker of store-operated calcium entry but an inconsistent inhibitor of ins (1,4,5) P₃-induce Ca²⁺ release. FASEB J, 2002, 16(10): 1145-1145

[8] CollettiL M, RemickD G, BurtchG D, et al.. Role of tumor necrosis factor-alpha in the pathophysiologic alterations after hepatic ischemia/reperfusion injury in the rat. J Clin Invest, 1990, 85(6): 1936-1936

[9] AlpiniG, PhillipsJ O, VromanB, et al.. Recent advances in the isolation of liver cells. Hepatology, 1994, 20(2): 494-494

[10] BarrosL F, StutzinA, CalixtoA, et al.. Nonselective cation channel as effectors of free radical-induced rat liver cell necrosis. Hepatology, 2001, 33(1): 114-114

[11] FanC, ZwackaR M, EngelhardtJ F. Therapeutic approaches for ischemia/reperfusion injury in the liver. J Mol Med, 1999, 77: 577-577

[12] LosserM R, PayenD. Mechanisms of liver damage. Semin Liver Dis, 1996, 16(4): 357-357

[13] BroadL M, BraunF J, LivremontJ P, et al.. Role of phospholipase C-inositol 1, 4, 5-trisphosphate pathway in calcium release-activated calcium current and capacitative calcium entry. J Biol Chem, 2001, 276(19): 15 945-15 945

[14] TrebakM, St J BirdG, McKayR R, et al.. Signaling mechanism for receptor-activated canonical transient receptor potential 3 (TRPC₃) channels. J Biol Chem, 2003, 278(18): 16 244-16 244

[15] ChaphamD E, RunnelsL W, StrubingC. The TRP ion channel family. Nature Reviews Neuroscience, 2001, 2(6): 387-387

[16] MaH T, PattersonR L, Van RossumD B, et al.. Requirement of the inositol triphosphate receptor for activation of store-operated Ca²⁺ channels. Science, 2000, 287(5458): 1647-1647

[17] KukkonenJ P, LundP E, AkermanK E. 2-aminoethoxydiphenylborate reveals heterogeneity in receptor-activated Ca²⁺ discharge and store-operated Ca²⁺ influx. Cell Calcium, 2001, 30(2): 117-117